Backlight unit, liquid crystal display apparatus using the same, and light-emitting diode used therefor

There are provided light-emitting layer provided on transparent substrate and emitting light of a specific wavelength, first reflecting layer formed on a light exit side relative to light-emitting layer and including a function of reflecting light emitted from light-emitting layer, second reflecting layer provided on a side of substrate in a manner to interpose light-emitting layer between first reflecting layer and second reflecting layer; light diffusion layer that diffuses light emitted from light-emitting layer is disposed between first reflecting layer and second reflecting layer; and second reflecting layer is formed of a high reflective metallic layer formed of a metallic film having a high reflectivity, a low refractive index layer formed of a material film having a low refractive index, and a multilayer-film reflective layer formed by laminating films made of materials having different reflectivity.